A study was carried out to ascertain the diffusion and adsorption parameter values for tritiated water in contact with palladium-silver cathodic membranes with and without palladium black deposits. It is shown that the amount of diffused and trapped tritium, the retrodiffusion, diffusion coefficient, tritium concentrations in the alloy sublayer; and diffusion layer thickness depend on the applied cathodic potential, temperature, palladium-silver membrane thickness, palladium black deposits on the cathodic surface, and time. With a palladium black deposit on the palladium-silver; the tritium adsorption and diffusion increase. Parameter values including the activation energy are determined from electrochemical impedance spectroscopy voltammetry: permeation experiments, and chronocoulometry.